Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature

Systemic ALK-negative anaplastic large cell lymphoma: Insights into morphologic, immunophenotypic, genetic and molecular characteristics

Anaplastic large cell lymphoma (ALCL) is a mature T-cell neoplasm characterized by large pleomorphic cells, often with horseshoe- or kidney-shaped nuclei and abundant cytoplasm (hallmark cells), and uniformly strong CD30 expression. Based on ALK expression or ALK rearrangement, ALCL is further classified into ALK-positive (ALK+) and ALK-negative types. This review focuses on the clinicopathologic, immunophenotypic, cytogenetic and molecular features of systemic ALK-negative ALCL. These patients are usually older adults who present with advanced stage disease and often a poor prognosis. ALK-negative ALCL is morphologically indistinguishable from the common pattern of ALK+ ALCL, but some cases show non-common morphology, such as "donut cells", Hodgkin-like features. ALK-negative ALCL is often negative for T-cell antigens (so-called "antigen loss") and in some cases can have a "null" immunophenotype and be confused with other hematopoietic and non-hematopoietic neoplasms. Recurrent genetic/molecular alterations have been identified in systemic ALK-negative ALCL, including rearrangements of DUSP22, TP63, JAK2, FRK, MYC, ROS1 and TYK2; mutations of JAK1, STAT3 and MSCE; and aberrant expression of ERBB4. Some of these alterations may have prognostic significance and/or provide potential therapeutic targets. Data support the idea that ALK-negative ALCL with DUSP22 rearrangement is a distinctive variant due to its unique morphologic, immunophenotypic and molecular features. Gene expression profiling data have shown that ALK-negative ALCL has distinctive molecular signatures, different from ALK+ ALCL and other T-cell lymphomas. Better understanding of the morphologic, immunophenotypic, genetic and molecular features of ALK-negative ALCL will help establish the correct diagnosis, guide therapeutic strategies and improve patient outcomes.

Strategy for Pediatric Patients with Relapsed or Refractory Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma: A Review

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) is an aggressive T-cell lymphoma characterized by large T-cells with strong CD30 and ALK expression. Although conventional chemotherapy is effective in most patients, approximately 30% experience a relapse or refractory disease and have a poor prognosis. Several risk factors associated with poor prognosis have been identified in pediatric ALK-positive ALCL. These include morphological patterns with the small cell variant or lymphohistiocytic variant, leukemic presentation, the presence of minimal disseminated disease, or involvement of the central nervous system. Relapsed or refractory ALK-positive ALCL is often resistant to conventional chemotherapy; therefore, salvage therapy is required. In recent years, targeted therapies such as ALK inhibitors and brentuximab vedotin (BV) have been developed. ALK inhibitors block the continuous activation of ALK kinase, a driver mutation that leads to cell proliferation in ALK-positive ALCL. Additionally, BV is an antibody-drug conjugate that targets CD30-positive cells. Both ALK inhibitors and BV have displayed dramatic effects in chemoresistant ALK-positive ALCL. Weekly vinblastine treatment and hematopoietic stem cell transplantation have also been reported to be effective therapies. This article reviews pediatric ALK-positive ALCL, focusing on risk factors and treatment strategies for pediatric patients with relapsed or refractory ALK-positive ALCL.

Leukaemic Presentation of Small-Cell Alk-Positive Anaplastic Large Cell Lymphoma in a Young Woman-Report of a Case with 9-Year Survival

Anaplastic large cell lymphoma (ALCL) with leukaemic presentation (either ab initio or along the course of the disease) has been rarely reported. Irrespective of ALK expression in the neoplastic cells, it features a dismal prognosis. We report a rare case of leukaemic, small cell variant ALK-positive ALCL with 9-year survival in a young woman who was treated upfront with corticosteroids and standard chemotherapy, and review thoroughly the previously published cases. Such an unexpected, good outcome hints at the existence of different clinical subgroups in the leukaemic variant of ALK-positive ALCL.

Leukemic High Grade B Cell Lymphoma is Associated With MYC Translocation, Double Hit/Triple Hit Status, Transformation, and CNS Disease Risk: The Mayo Clinic Experience

INTRODUCTION

Leukemic involvement in high grade B cell lymphoma (L-HGBL) is rare and has been sparsely described in the literature. We report our experience in a large single institution multicenter academic setting.

MATERIALS AND METHODS

Medical records of patients with HGBL who received care at Mayo Clinic between 2003 and 2020 were reviewed. L-HGBL was confirmed by peripheral blood smear and flow cytometry with corroboration from tissue and bone marrow biopsy findings.

RESULTS

Twenty patients met inclusion criteria. All patients had significant bone marrow involvement by HGBL. Leukemic involvement presented in 11 of 20 (55%) in the de novo and 9 of 20 (45%) in the relapsed setting. Seven of 20 patients had DLBCL, NOS, 6 of 20 had transformation (t-DLBCL), 3 of 20 had transformed double/triple hit lymphoma (t-DHL/THL), 2 of 20 had double hit lymphoma (DHL), and 2 of 20 had HGBL with intermediate features between DLBCL and Burkitt lymphoma. Nine of 15 patients had MYC translocation. Based on Hans criteria, 11 of 20 had germinal center B-cell (GCB) cell of origin (COO) and 9/20 had non-GCB COO. Five of 11 de novo patients experienced CNS relapse/progression. All de novo patients received anthracycline-based chemoimmunotherapy. Eighteen of 20 patients died of progressive disease. Median overall survival was significantly better in the de novo compared to relapsed group (8.9 months vs. 2.8 months, P = .01). COO, MYC status, DHL/THL status, HGBL subtype, or treatment group did not demonstrate a significant effect on overall survival.

CONCLUSION

L-HGBL carries a poor prognosis and is associated with MYC translocation, DHL/THL status, transformation, and high CNS risk. Novel therapeutic approaches are needed for L-HGBL.

Small cell/lymphohistiocytic morphology is associated with peripheral blood involvement, CD8 positivity and retained T-cell antigens, but not outcome in adults with ALK+ anaplastic large cell lymphoma

Several morphologic variants of ALK+ anaplastic large cell lymphoma (ALCL) are recognized. The small cell (SC) and lymphohistiocytic (LH) variants are reported to be associated with poorer outcome in children with ALK + ALCL. In this study of 102 adults with ALK + ALCL, there were 18 (18%) cases of SC and/or LH variants. Patients with SC/LH ALK + ALCL more often had peripheral blood involvement than patients with non-SC/LH neoplasms (60% vs 0%, p = 0.02). There were no other significant differences in clinical features between patients with SC/LH versus non-SC/LH ALK + ALCL. Compared with non-SC/LH cases of ALK + ALCL, neoplasms with SC/LH features were more often positive for CD2 (92% vs. 36%, p = 0.0007), CD3 (81% vs. 15%, p = 0.0001), CD7 (80% vs. 37%, p = 0.03), and CD8 (54% vs. 7%, p = 0.0006). There were no other significant differences in the immunophenotype between SC/LH and non-SC/LH ALK + ALCL cases. The initial chemotherapy regimens and the response rates were similar between patients with ALK + ALCL with SC/LH patterns versus those with non-SC/LH patterns. After a median follow-up of 30.8 months (range, 0.3-208 months), patients with high (>3) International Prognostic Index (IPI) scores had significantly shorter overall survival than patients with low (<3) IPI scores (p = 0.003). However, there was no significant difference in overall or progression-free survival between patients with SC/LH versus non-SC/LH ALK + ALCL (p = 0.99 and p = 0.94, respectively). We conclude that, in adults with ALK + ALCL, SC and LH variants are associated with peripheral blood involvement and a CD8 + immunophenotype with retention of T-cell markers (CD2, CD3, and CD7). However, in contrast with children with ALK + ALCL, SC and LH variants appear to have no impact on prognosis in adults with ALK + ALCL.

The Leukemic Phase of ALK-Negative Anaplastic Large Cell Lymphoma Is Associated with CD7 Positivity, Complex Karyotype, TP53 Deletion, and a Poor Prognosis

Simple Summary

Anaplastic large cell lymphoma (ALCL) is a systemic peripheral T-cell neoplasm characterized by strong and uniform CD30 expression and, usually, the aberrant loss of one or more T-cell antigens. ALCL is further classified into anaplastic lymphoma kinase (ALK)-positive and ALK-negative types. ALCL rarely involves the peripheral blood. The reported leukemic phase ALCL cases are almost all pediatric patients with ALK-positive ALCL, which are frequently associated with the small cell morphology, t(2;5)(p23;q35), and a poorer prognosis. Leukemic phase ALK-negative ALCL is extremely rare, with approximately ten cases reported in the literature to date, mostly as single case reports. Here we report on nine patients with leukemic ALK-negative ALCL—the largest case series to date—and we compare these cases with 39 non-leukemic cases of ALK-negative ALCL. We show that the patients with leukemic ALK-negative ALCL have a greater frequency of absolute lymphocytosis, thrombocytopenia, bone marrow involvement, CD7 positivity, complex karyotype, TP53 deletion, and a dismal outcome. These data suggest that leukemic phase ALK-negative ALCL is associated with a number of poor prognostic factors and affected patients may need more aggressive treatment.

Abstract

Patients with anaplastic large cell lymphoma (ALCL) rarely develop a leukemic phase of the disease. The reported leukemic ALCL cases are almost all ALK-positive, which are frequently associated with small cell morphology, t(2;5)(p23;q35), and a poorer prognosis. Rare leukemic ALK-negative ALCL cases have been reported. In the present study, we investigated the clinical and pathologic features and outcomes of nine patients with leukemic ALK-negative ALCL and compared these features with 39 patients without leukemic disease. Compared with the non-leukemic ALK-negative ALCL group, patients with leukemic disease more often had absolute lymphocytosis (50% vs. 0%, p = 0.008), thrombocytopenia (60% vs. 11%, p = 0.03), bone marrow involvement (50% vs. 14%, p = 0.04), and CD7 positivity (71% vs. 19%, p = 0.02). Four of five (80%) patients with leukemic ALK-negative ALCL had a complex karyotype, which was significantly higher than that of the patients in the non-leukemic group. A fluorescence in situ hybridization for TP53 was performed on six leukemic ALK-negative ALCL cases and all (100%) had TP53 deletion. There were no significant differences in the other clinicopathologic features, treatment, and complete remission rates between patients in the leukemic versus non-leukemic group (all p > 0.05). The median follow-up of this cohort was 18 months with a range of 0.3–140 months. Eight of nine (90%) patients with leukemic ALK-negative ALCL died, and their overall survival was significantly shorter than that of the patients with non-leukemic disease (median 15.5 vs. 60 months, p = 0.001). In conclusion, we show that the leukemic phase of ALK-negative ALCL is associated with high-risk biologic features and, in particular, a complex karyotype and TP53 deletion. Compared with the non-leukemic ALK-negative ALCL patients, the patients with a leukemic phase of disease have poorer survival and may require more aggressive treatment.

Diagnosis of the leukemic phase of ALK-positive anaplastic large cell lymphoma by immunohistochemistry on cell block prepared from peripheral blood buffy coat

A leukemic phase of anaplastic lymphoma kinase positive anaplastic large cell lymphoma (ALK+ ALCL) is rare. The leukemic cells morphologically appear as small to intermediate-sized cells with cerebriform and cloverleaf-like nuclei and are misdiagnosed as other T-Cell lymphomas/leukemia with similar morphology. We describe a case where the diagnosis of leukemic ALK+ ALCL was aided by immunohistochemistry performed on the cell blocks prepared from the peripheral blood buffy coat specimen. The diagnosis of ALK+ ALCL was further confirmed on the biopsy of a cutaneous nodule of this patient. We found the method of immunohistochemistry on peripheral blood buffy coat cell block very useful and suggest that it may be used as an alternative method to flowcytometry in low resource settings.

Rapidly progressing primary pulmonary lymphoma masquerading as lung infectious disease: A case report and review of the literature

BACKGROUND

Primary anaplastic large cell lymphoma of the lung represents a diagnostic challenge due to diverse manifestations and non-specific radiological findings, particularly in cases that lack extra-pulmonary manifestations and lung biopsy.

CASE SUMMARY

A 40-year-old woman presented with a 6-d history of fever, dry coughing, and dyspnea. Her white blood cell count was 20100/mm3 with 90% neutrophils. PaO2 was 60 mmHg and SaO2 was 90% when breathing ambient air. Chest computed tomography (CT) identified a solid nodule, 15 mm in diameter, with a poorly defined boundary in the upper right lung, and several smaller solid nodules throughout both lungs. Pulmonary artery CT and subsequent bedside X-ray showed diffuse patchy shadows throughout both lungs. Repeated cultures of blood samples and alveolar lavage failed to identify any pathogen. Due to the mismatch between clinical and imaging features, we conducted a bone marrow biopsy, and the results showed proliferation along all three lineages but no atypical or malignant cells. The patient received empirical antibacterial, antiviral, and antifungal treatments, as well as corticosteroids. The patient's condition deteriorated rapidly despite treatment. The patient died 6 d after hospitalization due to respiratory failure. Post-mortem lung biopsy failed to show inflammation but identified widespread infiltration of alveolar septum by anaplastic lymphoma kinase (ALK)-positive anaplastic cells.

CONCLUSION

ALK-positive anaplastic large cell lymphoma could present as a primary pulmonary disease without extra-pulmonary manifestations.

T-cell neoplasms in the spleen

Hematopoietic neoplasms involving the spleen are uncommon, but T cell neoplasms involving the spleen are extremely rare. The rarity of splenic involvement by T cell neoplasms has resulted in a limited body of literature describing their splenic characteristics. As a result, our purpose in this review article is to provide and summarize some of the characteristics seen by different T cell neoplasms that may involve the spleen.

Decreased MYC-associated factor X (MAX) expression is a new potential biomarker for adverse prognosis in anaplastic large cell lymphoma

MYC-associated factor X (MAX) is a protein in the basic helix-loop-helix leucine zipper family, which is ubiquitously and constitutively expressed in various normal tissues and tumors. MAX protein mediates various cellular functions such as proliferation, differentiation, and apoptosis through the MYC-MAX protein complex. Recently, it has been reported that MYC regulates the proliferation of anaplastic large cell lymphoma. However, the expression and function of MAX in anaplastic large cell lymphoma remain to be elucidated. We herein investigated MAX expression in anaplastic large cell lymphoma (ALCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) and found 11 of 37 patients (30%) with ALCL lacked MAX expression, whereas 15 of 15 patients (100%) with PTCL-NOS expressed MAX protein. ALCL patients lacking MAX expression had a significantly inferior prognosis compared with patients having MAX expression. Moreover, patients without MAX expression significantly had histological non-common variants, which were mainly detected in aggressive ALCL cases. Immunohistochemical analysis showed that MAX expression was related to the expression of MYC and cytotoxic molecules. These findings demonstrate that lack of MAX expression is a potential poor prognostic biomarker in ALCL and a candidate marker for differential diagnosis of ALCL and PTCL-NOS.

T-cell lymphoproliferative processes in the spleen

T-cell lymphoproliferative processes in the spleen are rare and it is important to study normal T cell subsets in the spleen to understand the splenic milieu in which they arise. True malignant T-cell processes including hepatosplenic T-cell lymphoma and T-cell large granular lymphocytic leukemia occur in the spleen, but other atypical reactive T-cell proliferations and those of uncertain significance also have been described. Proper distinction of florid T cell responses from malignant T-cell neoplasms has important therapeutic implications for the patient.

Pathology and genetics of anaplastic large cell lymphoma

Anaplastic large cell lymphomas are a rare subtype of peripheral/mature T-cell lymphomas which are clinically, pathologically and genetically heterogeneous. Both ALK-positive (ALK+) and ALK-negative (ALK-) ALCL are composed of large lymphoid cells with abundant cytoplasm and pleomorphic features with horseshoe-shaped and reniform nuclei. ALK+ ALCL were considered as a definite entity in the 2008 World Health Organization classification of hematopoietic and lymphoid tissues. ALK-ALCL was included as a provisional entity in the WHO 2008 edition and in the most recent 2017 edition, it is now considered a distinct entity that includes cytogenetic subsets that appear to have prognostic implications (e.g. 6p25 rearrangements at IRF4/DUSP22 locus). ALK+ ALCLs are distinct in epidemiology and pathogenetic origin and should be distinguished from ALK-ALCL, cutaneous ALCL and breast implant associated ALCL which have distinct clinical course and pathogenetic features. Breast implant-associated ALCL is now recognized as a new provisional entity distinct from other ALK-ALCL; notably that it is a noninvasive disease associated with excellent outcome. In this article, we will provide an overview of the salient themes relevant to the pathology and genetic mechanisms in ALCL.

Convergent mutations and kinase fusions lead to oncogenic STAT3 activation in anaplastic large cell lymphoma

A systematic characterization of the genetic alterations driving ALCLs has not been performed. By integrating massive sequencing strategies, we provide a comprehensive characterization of driver genetic alterations (somatic point mutations, copy number alterations, and gene fusions) in ALK(-) ALCLs. We identified activating mutations of JAK1 and/or STAT3 genes in ∼20% of 88 [corrected] ALK(-) ALCLs and demonstrated that 38% of systemic ALK(-) ALCLs displayed double lesions. Recurrent chimeras combining a transcription factor (NFkB2 or NCOR2) with a tyrosine kinase (ROS1 or TYK2) were also discovered in WT JAK1/STAT3 ALK(-) ALCL. All these aberrations lead to the constitutive activation of the JAK/STAT3 pathway, which was proved oncogenic. Consistently, JAK/STAT3 pathway inhibition impaired cell growth in vitro and in vivo.

A novel patient-derived tumorgraft model with TRAF1-ALK anaplastic large-cell lymphoma translocation

Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kB (NFkB) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies.

Paediatric anaplastic large cell lymphoma with leukaemic presentation in children: a report of nine French cases

This study aimed to describe the clinical features and outcome of anaplastic large cell lymphoma (ALCL) with leukaemic presentation in children. Among 267 patients included in the French paediatric ALCL database between 1989 and 2012, nine (3%) were described as having cytologically detectable circulating tumour cells. Clinical features combined fever (8/9), nodal and extra-nodal disease (9/9), including hepato-splenic (9/9) and lung involvement (7/9). The level of hyperleucocytosis ranged from 30 to 120 × 10(9) /l, with 12-90% of tumour cells. Diagnosis relied on a lymph node biopsy, with a positive ALK+ antibody immunostain in all nine cases, a T-cell immunophenotype in 7/9 cases and CD3 positivity in 5/9 cases. A small cell component was present in 6/9 cases. Only four patients achieved a complete remission with first-line therapy and 3/4 relapsed. Four patients are alive with a median follow-up of 31 months, two of them after allogeneic haematopoietic stem cell transplantation (HSCT), and five patients died, two of them of disease. In conclusion, ALCL with leukaemic presentation is very unusual and should be considered as high-risk lymphoma requiring new therapeutic strategies. The respective role of new agents and allogeneic HSCT in first complete remission still has to be assessed.

Beyond NPM-anaplastic lymphoma kinase driven lymphomagenesis: alternative drivers in anaplastic large cell lymphoma

PURPOSE OF REVIEW

Anaplastic large cell lymphomas (ALCLs) are rare entities whose somatic genetic lesions have been identified only in a subset of patients. Thus, an integrated and massive discovery programme is required to define their tumourigenic alterations and to design more successful tailored therapies.

RECENT FINDINGS

The discovery of anaplastic lymphoma kinase (ALK) fusions has provided the basis for the characterization of distinct subsets among ALCL patients. Although the oncogenic addiction of ALK signalling is proven, the tumorigenic contribution of coactivating lesions is still missing. As ALK- and ALK+ share common signatures, it is plausible that analogous mechanisms of transformation may be operating in both subsets, as confirmed by the dysregulated activation of c-MYC, RAS and NFκB, and the loss of Blimp-1 and p53/p63 axis. Nonetheless, recurrent genetic alterations for ALK- ALCL or refractory leukaemic ALK+ ALCL are lacking. Moreover, although conventional chemotherapies (anthracycline-based) are most successful, that is in ALK+ ALCL patients, the implementation of ALK inhibitors or of anti-CD30 based treatments provides innovative solutions, particularly in paediatric ALK+ ALCL and in chemorefractory/relapsed patients.

SUMMARY

The complete portrayal of the landscape of genetic alterations in ALCL will dictate the development of innovative chemotherapeutic and targeted therapies that will fit most with the molecular and clinical profiling of individual patients.

Anaplastic large cell lymphoma with paraneoplastic leukocytosis: a clinicopathological analysis of five cases

Anaplastic large cell lymphoma (ALCL) is a type of T-cell lymphoma with a relatively favorable prognosis. However, a certain group of ALCLs is highly aggressive, featuring paraneoplastic leukocytosis (PL) in clinical presentation. The present study evaluated five cases of ALCL presenting with PL, including four men and one woman, with a median age of 58 years. All cases revealed leukocytosis with a range from 15.3 to 112.9 × 10(3) /μL. Five (100%) and 4 (80%) cases demonstrated immunoreactivity for granulocyte-colony-stimulating factor (G-CSF) and tumor necrosis factor-alpha (TNF-α), respectively. There were significant differences in the expression of G-CSF and TNF-α between ALCL cases with or without PL (p < 0.05 for both). The prognosis of ALCL patients with PL was poor. Four of five patients (80%) died of the disease within a median survival time of 3.5 weeks. The release of G-CSF and TNF-α from lymphoma cells may associate with ALCL presenting with PL, leading to cytokine crisis and even poorer prognosis.

Cutaneous anaplastic large-cell lymphoma should be evaluated for systemic involvement regardless of ALK-1 status: case reports and review of literature

Anaplastic large-cell lymphoma (ALCL) is a lymphoma that expresses CD30. Cutaneous ALCL presents either as primary cutaneous disease or as secondary skin involvement due to the systemic disease. Herein, we describe two patients who presented to dermatology for evaluation of skin lesions diagnosed by non-dermatologists as a cutaneous abscess and lupus erythematosus, respectively. Upon investigation by a team of medical dermatologists and dermatopathologists, systemic ALCL with secondary skin involvement was discovered in both patients. The majority of cases of systemic ALCL with cutaneous involvement express anaplastic lymphoma kinase-1 (ALK-1), and are associated with a more favorable prognosis than ALK-1-negative cases. However, cutaneous ALCL regardless of ALK-1 status may be secondary to systemic lymphoma. This article stresses the importance of dermatologists being aware of the diagnosis of systemic lymphoma based on cutaneous findings, and being aggressive in initiating appropriate diagnostic testing. Primary cutaneous ALCL and systemic ALCL are reviewed.

The small cell variant of anaplastic large cell lymphoma

Anaplastic large cell lymphomas constitute a heterogeneous group of hematopoietic neoplasms that are characterized by immunopositivity for CD30 and the presence, in varying degrees, of large, pleomorphic "hallmark" cells. Primary systemic anaplastic lymphoma kinase-positive anaplastic large cell lymphomas are a subset of this group. Numerous heterogeneous histomorphologic patterns have been described in anaplastic lymphoma kinase-positive anaplastic large cell lymphomas, and all patterns tend to have a better prognosis than that found in anaplastic lymphoma kinase-negative cases. We provide a short review of the small cell variant of anaplastic large cell lymphoma to facilitate the diagnosis of this difficult-to-recognize entity, which may be confused with reactive processes, commonly presents with disseminated disease, and pursues an aggressive clinical course.

A practical approach to the flow cytometric detection and diagnosis of T-cell lymphoproliferative disorders

The flow cytometric analysis of T-cell malignancies is difficult due to the heterogeneity of T-cells and the lack of convenient methods to detect T-cell clonality. Neoplastic T-cells are most often detected by their altered level of surface antigen expression, and detection requires an extensive knowledge of the phenotype of normal T-lymphocytes. This review focuses on the methods to distinguish malignant T-cells from their normal counterparts and the phenotypic features of the T-cell lymphoproliferative disorders.

Anaplastic large cell lymphoma in leukemic phase: extraordinarily high white blood cell count

Anaplastic large cell lymphoma (ALCL) is a distinct type of T/null-cell non-Hodgkin lymphoma that commonly involves nodal and extranodal sites. The World Health Organization of lymphoid neoplasms recognizes two types: anaplastic lymphoma kinase (ALK) positive or ALK negative, the former as a result of abnormalities involving the ALK gene at chromosome 2p23. Patients with ALCL rarely develop a leukemic phase of disease, either at the time of initial presentation or during the clinical course. Described herein is a patient with ALK+ ALCL, small cell variant, associated with the t(2;5)(p23;q35), who initially presented with leukemic involvement and an extraordinarily high leukocyte count of 529 x 10(9)/L, which subsequently peaked at 587 x 10(9)/L. Despite chemotherapy the patient died 2(1/2) months after diagnosis. In the literature review 20 well-documented cases are identified of ALCL in leukemic phase reported previously, with a WBC ranging from 15 to 151 x 10(9)/L. Leukemic phase of ALCL occurs almost exclusively in patients with ALK+ ALCL, most often associated with the small cell variant and the t(2;5)(p23;q35), similar to the present case. Patients with leukemic phase ALK+ ALCL appear to have a poorer prognosis than most patients with ALK+ ALCL.

Anaplastic large cell lymphoma in leukemic presentation: a case report and a review of the literature

It is extremely rare that a patient with anaplastic large cell lymphoma (ALCL) demonstrates circulating lymphoma cells. A 10-year-old Japanese boy was presented with high-grade fever and cough. The physical examination revealed marked hepatosplenomegaly with ascites and lymphadenopathy in the cervical and periauricular areas. The white cell count was 26.2x10(9)/L with 95% of abnormal lymphoid cells, which were small to medium-sized with a high nucleus/cytoplasm ratio, basophilic cytoplasm, condensed nuclear chromatins, and 1 or 2 distinct nucleoli, hemoglobin 6.4 g/dL, and platelet 0.9x10(9)/L. A flow cytometric analysis of abnormal cells in both the peripheral blood and bone marrow samples was strongly positive for CD30 on their cell membranes. Karyogram and fluorescent in situ hybridization showed abnormal cells to have a characteristic chromosomal translocation, t(2;5)(p23;q35). Reverse transcriptase-polymerase chain reaction of peripheral blood cell-derived mRNA also indicated the fusion gene product of anaplastic lymphoma kinase and nucleophosmin. Subsequently, the patient was diagnosed to have ALCL with a rare clinical feature of a peripheral leukemic presentation, and his disease revealed to be refractory to chemotherapy. On the basis of the 11 childhood cases of ALCL with leukemic presentation so far published and reviewed herein, the prognosis is very poor.

A leukemic change as an initial manifestation of the common variant type of ALK-positive anaplastic large cell lymphoma in a patient with lung adenocarcinoma

We report an 81-year-old man who had leukemic presentation of ALK-positive anaplastic large cell lymphoma (ALCL) as an initial manifestation. He had been well after chemotherapy and irradiation for the advanced lung adenocarcinoma, but suddenly suffered from severe lactic acidosis and hypotension. The peripheral blood smear and bone marrow aspiration revealed the infiltration of atypical large cells with horseshoe-shaped or lobulated nuclei. The detection of CD30 expression and the t (2;5) (p23;q35) translocation in these cells was confirmatory of a diagnosis of common variant ALK-positive ALCL in a leukemic phase. He deteriorated rapidly and died before administration of the chemotherapy. An adequate, prompt diagnosis is necessary for this rare disease status in oncologic emergency to improve the disease management.